1. Field of the Invention
The present invention relates to a process for producing dihydroxyacetone kinase (referred to as DHAK) which is formed by strains of genus Schizosaccharomyces.
2. Decription of the Prior Art
DHAK is an enzyme which catalyzes the reaction of transferring the phosphate group of a phosphate donor to dihydroxyacetone (referred to as DHA) to form dihydroxyacetone phosphate. The equation of the reaction where adenosine triphosphate (referred to as ATP) is used as the phosphate donor is as follows: ##STR1##
The present inventors made extensive studies of the glycerol determination methods employing glycerol dehydrogenase. However, since the reaction catalyzed by glycerol dehydrogenase is reversible as given by the following equation, there has been a disadvantage such that, in order to promote the forward reaction, it is required to add excess nicotinamide adenine dinucleotide (referred to as NAD.sup.+) to the reaction mixture or conduct the reaction in as high a pH region as from 10 to 11. ##STR2##
For the purpose of promoting the forward reaction, it is desired to exclude the formed DHA from of the reaction system. Thus, the present inventors examined various enzymes suitable for the purpose, and found DHAK to be effective.
DHAK are known to occur in, for example, Candida methylica [Z. Allg. Mikrobiol., 20, 389 (1980); ibid., 21, 219 (1981)], Gluconobacter suboxidans (Joint Technical Meeting held by the Chubu Branch and the Kansai Branch of the Agricultural Chemical Society of Japan, Oct. 9, 1981, Abstract of the Lectures, p.3), Acetobacter xylinum (J. Bacteriol., 127, 747 (1976)), and Dunaliella, a green alga, (Plant Physiol., 59, 15 (1977)) and Biochim. Biophys. Acta, 615, 1 (1980)). However, these strains are unsatisfactory in the low productivity, the lack of enzyme stability, and the difficulty to obtain the highly purified enzyme preparation, etc.